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Basic Sustainable Design
Principles
Energy
Efficiency
Material Efficiency
Water Efficiency
Regional Design
Material Efficiency
Tons of materials, including thousands of board feet of lumber, go
into constructing an average home in the United States.
There are three principal approaches to improving the material efficiency of home
construction:
reducing the amount of material
used in construction;
using recycled materials that
otherwise would have been waste; and
reducing waste generated in the
construction process.
Reduce materials use
Several specific strategies can be employed to
reduce the amount of materials used in the construction of a home. Choosing material-efficient components and
assemblies is one means of achieving an overall materials reduction. For instance, using engineered lumber or steel
framing instead of solid wood reduces the total framing material use in a structure. Similarly, using roof trusses instead of framing a
roof with dimensional lumber saves material. Additionally,
individual resource-efficient materials—materials that do more with less—are an
important way to reduce materials use. Engineered
lumber I-joists are one example of a product that achieves greater strength from less
material than conventional building products. Reduce
materials use are conscious simplification of framing, space-efficient design principles
that allow smaller houses, and efficient floor plan layout that creates a central utility
core and minimizes wasted space.
Use recycled materials
Material efficiency also can be
achieved by using recycled materials in construction.
Not only does this help relieve the consumption pressure on dwindling supplies of
natural resources, but it also helps remove costly and problematic waste disposal
challenges by converting waste into useful new products.
Furthermore, recycled materials often require less energy to produce than new
building materials, so choosing recycled materials can help save both energy and material
resources. Recycled building materials can be
made from post-industrial or post-consumer recycled paper, wood, rubber, plastic, glass,
metal, and other products. Recycled products
can be used in the structure, interior and exterior finishes, and landscaping of homes.
Many directories of recycled building products exist, and these products are becoming more
widely available due to the increasing environmental awareness and commitment of building
material manufacturers and retailers. Even
greater energy and materials savings can be attained by reusing salvaged existing building
materials in a project rather than consuming new, or even recycled, building products.
Reduce waste
 There
are three main ways to reduce waste generated in the construction process. First, source reduction prevents material waste
before it happens. One example is designing
buildings on the 2-foot module, so that they can use standard sizes of material without
requiring the added labor and waste of cutting materials to fit on site. The technique is called Optimal Value Engineering
(OVE). The "OVE Manual" was developed under sponsorship of HUD by the NAHB
Research Center in 1977. " OVE is basically a procedure of comparing alternative
materials and methods to determine the least costly combination that will result in an
acceptable product. In the broadest sense, the OVE concept simply extends on the practice
to provide an effective, systematic total systems approach. In a narrow sense, it provides
a valuable reference to a wide variety of cost reducing techniques covering the entire
design and construction process." The updated version is titled; "Cost-Effective
Home Building." 1
Another means of avoiding waste at
the site is use of prefabricated construction systems such as "structural insulated
panels" or SIPs. Source reduction also includes careful, accurate materials
ordering to avoid leftover materials.
Despite the best efforts at source
reduction, there will be waste produced at any construction site, and particularly on job
sites that involve demolition of existing buildings.
Dealing with this waste by salvaging and reusing materials, and by recycling scrap
material and packaging, will re-supply the building materials market with material and
reduce the waste disposal costs for a building project.
Materials that can be salvaged for reuse include doors, brick, windows, glass
block, fixtures, beams, and some dimensional lumber.
Materials that can be recycled from the job-site include cardboard packaging and
metals. In some locations clean wood waste
and gypsum wallboard also can be recycled. Even
where they can’t be recycled, they can be ground and beneficially used on site as
soil amendment and mulch.
Next
Section: Basic Sustainable
Design Principles: Water Efficiency
1Cost-Effective Home Building, 1994. National Association of Home Builders
Research Center, NAHB Bookstore, 1201 – 15th Street, NW, Washington, DC 20005; (800)
223-2665.
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